Naslov
3D-mathematical modelling of limestone calcination

Autori
Mikulčić, Hrvoje ; Vujanović, Milan ; Duić, Neven

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Zbornik povzetkov Slovenski kemijski dnevi 2013 / Kravanja, Zdravko - Maribor, 2013

Skup
Slovenski kemijski dnevi 2013

Mjesto i datum
Maribor, Slovenija, 10.09.2013. - 12.09.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Calcination; limestone; numerical modelling

Sažetak
Calcination is an industrial process that uses high temperature to change the chemical and physical properties of limestone, a sedimentary rock composed of the mineral calcite - calcium carbonate and other mineral dolomites. The calcination process is used in many different industries today, such as cement, chemical, pharmaceutical and sugar industry, where limestone CaCO3 is converted by thermal decomposition into lime CaO and carbon dioxide CO2. This reaction is highly endothermic and requires combustion heat released by the fuel where the temperature is between 780°C to 1350°C, indicating that endothermic limestone calcinations and exothermic fuel combustion proceed simultaneously. Fluid flow, transport phenomena, and thermodynamics within these processes are still not well understood in detail. Therefore, understanding the mechanisms of fluid flow and transport phenomena is important. This paper presents 3D mathematical model of limestone calcination reaction mechanism, which was developed and implemented into a commercial code FIRE. The calcination model the effects of temperature, decomposition pressure, diffusion, and pore efficiency since dissociation of the limestone begins at the outer surface of the limestone particle and shifts inward, leaving a porous layer of lime at the surface. Limestone calcinations reactions are calculated using the Arrhenius rate equation for the liberation of CO2. The model is based on the solution of Navier-Stokes equations for the gas phase, and on the Lagrangean dynamics for the discrete particles. The information obtained by these numerical simulations, such as distribution of particles, distribution of temperatures and concentrations can be used for better understanding of particle kinetics and pollutant emissions from calcinations systems and also for investigation and optimization of calcination devices in various industries.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

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